Correlation of magnetic resonance and oxygen microelectrode measurements of carbogen-induced changes in tumor oxygenation
Correlation of magnetic resonance and oxygen microelectrode measurements of carbogen-induced changes in tumor oxygenation
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DOI：
10.1016/s0360-3016(98)00038-8
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发表时间：
1998-04-01
影响因子：
7
通讯作者：
Karczmar, GS
中科院分区：
文献类型：
--
作者：
Al-Hallaq, HA;River, JN;Karczmar, GS
目的：这项工作的目的是检验这一假设，即氧合治疗引起的肿瘤磁共振（MR）水信号线宽的降低是由于血红蛋白的毛细血管和静脉氧饱和度的增加，这与血管外氧分压（pO（2））的增加密切相关。为了建立这种联系，我们将MR测量的变化与在碳氧代谢过程中氧微电极直接测量的组织pO（2）的变化进行了比较。（95%O-2/5%CO2）吸入。9只大鼠的乳腺腺癌（R3230 AC）在4.7特斯拉下成像，T-1加权（TR = 200 ms，翻转角= 45度）通过每个肿瘤的单个切片中的水共振的光谱图像以3.9 Hz的光谱分辨率和+/-1000 Hz的带宽获得。在这些肿瘤中的相同切片中，使用具有350微米尖端的非克拉克型氧电极进行微电极测量。在交替吸入空气和二氧化碳的过程中进行MR和微电极测量。在碳源诱导的高氧下，水共振线宽显著降低，对微电极数据的配对t检验表明，pO（2）显著降低。（p < 0.05）由于吸入carbogen而增加，每个肿瘤的MR和微电极数据平均值表明，MR水信号线宽的降低与肿瘤的生长密切相关。（r = 0.92，p < 0.05）。结论：尽管肿瘤氧合剂增加了啮齿类肿瘤对放射的反应，但临床研究表明对人类肿瘤的放射敏感性只有轻微的影响。这可能部分是因为肿瘤氧合治疗的效果在每个肿瘤内和肿瘤群体之间都是高度异质性的。通过本工作验证的非侵入性高分辨率MR方法可以指导新的和更有效的肿瘤氧合剂的设计，并优化个体患者的治疗。(C)1998年爱思唯尔科学公司
Purpose: The aim of this work was to test the hypothesis that decreases in the linewidth of magnetic resonance (MR) water signals in tumors caused by oxygenating treatments are due to increases in capillary and venous oxygen saturation of hemoglobin, which are tightly coupled to increases in extravascular oxygen tension (pO(2)). To establish this link, changes measured by MR were compared to changes in tissue pO(2) measured directly by oxygen microelectrodes during carbogen (95% O-2/5% CO2) inhalation.Methods and Materials: Mammary adenocarcinomas (R3230AC) in nine rats were imaged at 4.7 Tesla, T-1-weighted (TR = 200 ms, flip angle = 45 degrees) spectroscopic images of the water resonance in a single slice through each tumor were acquired with spectral resolution of 3.9 Hz and bandwidth of +/-1000 Hz, In the same slices in these tumors, microelectrode measurements were made using a non-Clark style oxygen electrode with a 350-micron tip. MR and microelectrode measurements were made during alternating periods of air and carbogen inhalation.Results: Water resonance linewidth decreased significantly during carbogen-induced hyperoxia, Paired Student's t-test analysis of microelectrode data indicated that pO(2) was significantly (p < 0.05) increased as a result of carbogen inhalation, MR and microelectrode data averaged over each tumor demonstrated that decreased MR water signal linewidth is strongly correlated (r = 0.92, p < 0.05) with increased tumor pO(2) levels.Conclusion: Although tumor oxygenating agents increase response to radiation in rodent tumors, clinical studies have shown only marginal effects on the radiosensitivity of human tumors. This may be, in part, because the effects of tumor oxygenating treatments are highly heterogeneous both within each tumor and among a population of tumors. The noninvasive, high-resolution MR methods that are validated by the present work could guide the design of new and more effective tumor oxygenating agents and optimize treatments for individual patients. (C) 1998 Elsevier Science Inc.